Lumber and article made therefrom



Oct. 29, 1935. A. ELMENDORF LUMBER ANDVARTICLE MADE THEREFROM Filed June14, 1935 2 sheets-sheet 1 Oct. 29, 1935. A. ELMENDORF LUMBER AND ARTICLEMADE THEREFROM 2 sheets-sheet z Filed June 14, 1933 lsatented Oct. 29,1935 Application .tune is, ms, semi No. cresca Claims.

The present invention has for its object to produce a simple and novelconstruction material in the form of thin integral wood panels orsheets, comprising narrow strips arranged edge to edge and exiblyconnected together, whereby warping of the panels or sheets is avoidedand capacity for expansion and contraction across the grain of the woodis provided.

in carrying out my invention I cut part way through the thickness of asheet or panel of wood along `parallel lines extending from. end to endin the general direction oi' the grain of the wood, thereby dividing thesheet or panel superficially into a series of narrow strips. The sheetor panel is then stressed across the grain to the rupture point, causingthe comparatively thin connecting webs between the strip-like sectionsto divide themselves into small strands each attached at its ends toboth of thee-adjacent sections. The cutting and the rupturing mayconveniently be performed as a single operation. Thus, by using a knifewedge=shaped in cross section and cutting into the wood iar enough, butonly far enough, to rupture the remaining uncut depth, the connestingstrands between the narrow wood strips are produced as part of thecutting operation. The strands hold the sections of the sheet or paneltogether; destroy the capacity o the sheet or panel to warp; and permitthe sheet or panel to be stretched, if desired, across the grain untilthere appear between adjacent strips or sections distinct gaps acrosswhich the strands extend.

It will be obvious that my improved material lends itself to a greatvariety of uses. Thus, a flooring may be made of wood of a proper kind,stretched so as to open definite gaps between the strips and having thegaps illled with an eiastic material bonded to the wood; thereby makingpossible the use of wide, thin floor boards that would otherwise beuseless for that purpose. Made in sumciently large sheets and` of cheapwood, faced on one side with strong paper, or the like, my improvedmaterial may be employed to advantage to form inexpensive foldable boxesor shipping containers.

Although the invention is not limited to these particular fields, it maybe said to have for an object the production of a novel flooringmaterial and, for another object, the production of a novel box orshipping container.

In making a flooring material, wood sheets or panels, preferablyfromone-eighth to one-quarter of Van inch thick, properly cut andexpanded so as to open up gaps between adjacent strips, are preferablypressed down upon a body of plastic material; causing the lling materialto rise into and ll the gaps. The filling material, in order to obtainthe full advantages of my invention, must be elastic and of a type thatbonds itself to the wood, thereby preventing the opening of cracks undersubsequent expansion `and contraction of the wood. The filling materialshould also be wa.- terprooi. I have found that rubber in latex formanswers the requirements just enumerated, and I therefore prefer toemploy such latex as the filler, 5 mixing with the latex a substancethat will harden the mass sumciently to permit sanding of the door.Fm'thermore, the under side of the oor board as a whole is preferablywaterproofed; this being conveniently accomplished by giving it a l0surface coating of latex, or by gluing the board to waterproofed felt orthe like. 1f the wood be very dry, having a moisture content of not morethan three or four percent at the time of manufacturing the ooringmaterial, and is backed as l5 aforesaid, the board develops a slightlycurved shape, the exposed wood face being on the convex side. Such aboard, when applied to a foundation, can be held down in a flatcondition, without the use of weights, by means oi ordinary linoieumcements.

The various features of novelty whereby my invention is characterizedwill hereinafter be pointed out with particularity in the claims; but,for a full understanding of my invention and oi' 25 its objects andadvantages, reference may be had to the following detailed descriptiontaken in connection with the accompanying drawings, wherein:

Figure l is a plan view of a thin panel oi wood slitted part way throughthe same; Fig. 2 is a section, on a greatly enlarged scale, on line 2 2of Fig. l; Fig. 3 ls a view similar to Fig. 2, showing the condition ofthe panel after the rupturing of the connecting webs between thestrip-like sections and the stretching of the panel to open up gapstherein; Fig. 4 is a top plan view of the fragment shown in Fig. 3; Fig.5 is a section similar to and on the same scale as Figs. 2 and 3,illustrating a panel in the condition that itis in after it has beenstressed across the grain to the rupture point and has then been gluedto a paper backing; Fig. 6 is a view similar to Fig. 3, showing the gapsilled with a suitable filling material; Fig. 7 is a view similar to Fig.6, showing the ll- 45 ing material continued over a face of the panel toform a facing layer; Fig. 8 is a perspective View of a fragment of acompleted flooring board or panel; Fig. 9 is a cross section on the samescale as Figs. 6 and 7 through the flooring board or panel, 50 showingonly a fragment thereof; Fig. 10 is a View similar to Fig. 9, showingthe board or panel bent without opening up the joints; Fig. 11 is a moreor less diagrammatic view illustrating a. method of producing thematerial of Fig. 8; Fig. 12 is 55 a perspective view of a box orshipping container embodying the present invention. in one of its forms;Fig. 13 is a section on line i3-l3 of Fig. 12, on a larger scale; Fig.14 is a section on line i4i4 of Fig. 12, the scale being the same asthat 6o of Fig. 13; `.and Fig. 15 is a transverse section through thepanel forming the body portion of the box. at the point where a corneris to appear when the panel is folded.

Referring to Figs. 1-4 of the drawings, I represents a thin panel ofwood which will usually be thick veneer. By means of slitting cutters, Icut part way through the same along parallel lines 2, 2 extending fromone end to the other. The cutting may be done from one or both sides, aslong as the result is to divide the wood into strips connected bycomparatively thin web portions. In Figs. 2-4 the cuts are shown asextending inwardly toward the center from both sides or faces, leavingunsevered web portions 3.

'Ihe panel is then stressed transversely of the 'grain to the rupturepoint, rupturing the web portions and dividing or partially dividingthem into strand-like elements. The material may now be expanded asillustrated in Figs. 3 and 4, producing comparatively wide gaps 5 acrosswhich extend the strands 6 by which the strip-like sections of the panelare held together. The strands are, of course, spaced apart from eachother so that the gaps or passages now extend entirely through the wood.

In Fig. 5 I have illustrated a material that may be used in theconstruction of boxes or the like. The panel 1 may be a veneer of' cheapwood having any desired thickness. Veneer about threesixteenths of aninch thick is suitable for use in the construction of the majority ofboxes or containers. It is unnecessary, for this purpose, to open upgaps in the wood, and therefore the panel is left in the condition towhich it is brought when stressed transversely of the grain to therupture point; the cuts or slits remaining practically closed, asindicated at 8, the strands into which the connecting webs 9 have beendivided being still in contact with each other and not yet having beenspread apart from each other. Glued toone face of the panel is a sheet IIl of tough paper or the like.

In Fig. 6 there is shown a panel II which. after having been brought tothe condition illustrated in Fig. 3, has the gaps therein filled with asuitable flling material, as indicated at I2. The filling material isintroduced into the gaps in a plastic condition and flows around theconnecting strands across the gaps, causing these strands to be embeddedwithin the filling material. The filling material, for most purposes,should be elastic and of such a character as to enable it to bond itselfwith the wood. I prefer to use rubber latex which is not only elasticbut adheres strongly to the wood. The filling in each gap may beregarded as an elastic membrane bonded to the edge faces of the stripsbetween which the gap lies. In most cases there should be mixed with thelatex a powdered or granular material such as ground mica, talc, orother suitable finely divided solid mineral. The addition -of suchminerals to the latex greatly facilitates the sanding of the boards orpanels in commercial sanding machines.

In order to insure that the filling material shall form solid bodies ormembranes in the gaps in the wood, I prefer that the wood be presseddown upon a mass or body of the filling material while the latter is ina plastic condition, causing the latter to be forced up into the gapsfrom below. I shall refer again to this step hereafter.

In Fig. 7 there is shown a construction like that of Fig. 6, exceptingthat there is on one side of the panel a flexible facing I3 which may bea thin layer of the same material as that which fills the gaps.

In Figs. 8-11 I have illustrated what I regard as the preferred form ofpanel, sheet, or board for use as a flooring, and the method of making 5the same. Referring to these figures, I4 is a sheet of flexible backingmaterial, such as waterproofed felt. Overlying and glued to this sheetis a thin board of wood that has been treated as heretofore described,to transform it into a series of 10 parallel strips I5, I5 spaced ashort distance apart from each other, but being connected together bystrands of Wood I 6 extending across the gaps I1 between the strips. Thecompleted product is shown in Fig. 8, while Fig. 11 illus- 15 trates thepreferred method of making it. When the backing layer I4 is feltsaturated with asphalt, the face toward the wood is preferably sized as,for example, with an oil size, to facilitate the bonding thereto of theadhesive that zo unites the felt and the wood. This bonding may beeffected still more readily and successfully by applying to the sizedface of the backing a thin layer of casein glue. Upon the glue is placedthe plastic latex, preferably by depositing small g5 masses, asindicated at I9 in Fig. 11, to avoid working the latex as is the casewhen the latex is spread as a thick uniform coat. In any event, afterthe latex has been applied to the backing, the wood board or panel islaid upon the same and forced down with suflicient pressure to cause thelatex to fiow up into the gaps or passages through the wood and createelastic membranes I2 bonded to the ewood. Some of the latex remainsbetween th`yiood and the backing and 35 forms with -the casein glue athin glue layer 20.

The gaps or passages through the wood in such embodiments of myinvention as those illustrated in Figs. 6 and 7 are also preferablyfilled in4 the manner just described, namely, the wood o being presseddown upon a mass of the latex compound or mixture.

Instead of filling the joints between the strips of the material shownin Figs. 6, 7, and 8 with latex, I may employ a drying oil or oils as,for 5 example, China-wood oil. Wherea drying oil is used it may bedeposited on the upper face of the wood panel and be caused to enter thejoints by running a scraper across the surface of the Wood. Compositionscontaining China-wood oil, 50 applied in this way, not only fill thejoints with elastic membranes bonded to the wood, but they also serve togive a finish to the wearing face of the panel. Ordinarily there must beseveral applications of the drying oils to effect a complete 55 fillingof the joints.

As heretofore stated, the elastic membranes I2 are bonded to the wood,so that the Wood strips may expand and contract without opening cracksbetween them. Also, if the board or panel is bent, 60 as indicated inFig. 10, the elastic membranes stretch in conformity with the alteredshapes of the passages through the wood, but remain bonded to the woodand do not separate therefrom.

The boards or panels of Figs. 6, 7, and, 8 may all be used as fiooring,although those of Figs. 7 and 8 are the bettersuited for application todamp foundations. Not only do the waterproof backings in theconstructions of Figs. 7 and 8 prevent moisture from reaching the woodfrom beneath. but they serve also as cushions which compensate forirregularities in the surface contour of the foundation on which theflooring rests.

In Figs. 12-15 I have shown a novel box construction employing plainwood panels that have 75 been slit into strips connected together bystrands and faced on one side with tough paper. The

strips have no appreciable gaps between them and the strands stillremain in contact with each other and form between the stripsconnections that still have the appearance of webs. The body of the boxis composed of a single panel, the wood veneer being indicated at 25 andthe paper at 26. The slits or cuts 2l are shown as extending into thewood from one face only. This composite sheet may conveniently beproduced by ilrst bringing the veneer and the paper facing together withwet glue between them, and then cutting the veneer in such a manner asto eiect the rupture of the depth left uncut in the wood. By thismethod, the paper prevents the individual strips from separating andcausing appreciable gaps to be formed.

V-shaped grooves 2B are cut into the wood element of the compositesheet, along lines paralleling the slits 21, wherever the panel requiresbending to produce a corner of the box. In the arrangement shown, thebox is four-sided, so that the panel has three of these V-grooves andmay therefore be folded into the form of a square or rectangular shellopen at both ends. The joint between the meeting ends of the foldedpanel is covered with a strong tape 29,- preferably of cloth, the tapebeing glued or cemented to the panel. One of the sides of the shellforming an end of the panel serves as the top or cover of the box, andtherefore the tape is applied only at the time the box is closed uponits contents.

At the long edges of the panel, namely, along the edges that constitutethe ends of the side walls of the shell or body member I place suitablecleats which cooperate to form strong end frames. Each cleat is made infour sections which, in the arrangement shown, are fashioned at theirends to produce miter joints when the panel is folded into shell form.Each cleat is composed of a core 30 of wood, square or rectangular incross section; three sides of the core being covered by the panelmaterial. The panel is made wide enough so that by cutting parallel witheach long edge two of the V-grooves, properly spaced, and cuttingV-shaped sections bodily out of the panel in registration with eachtransverse line of fold, the side marginal portions of the panel may befolded or wrapped around the core members: each core member and theenclosing elements thereafter being secured together, preferably bystaples 3|. The loose end Walls or box heads 32 t into the shell againstthe inner edges or faces of thecleats. These end walls or heads may beconstructed of any suitable material which I have illustrated asconsisting of wood veneer faced on both sides with strong paper.

The box is shipped in three flat pieces, namely, the pre-formed bodypanel and the two ends or heads, and is set up at the point of use. Insetting up the box, the body panel is folded along the lines of two ofthe transverse V-grooves and the end walls or heads `are set into the U-shaped structure thus produced. A few light nails are then driventhrough the end walls or heads into the upright cleats which are thecleats at the ends of the side walls of the box. After the box has beenfilled, the fourth side is folded down and is secured with the tape 29.The box may be reenforced with suitable ties or straps 33.

The material of which the body portion of the box is made lies fiatbefore being folded, even though the wood veneer originally was badlybuckled or warped. Furthermore, this material may be made in long sheetsby a continuous process of gluing pieces of veneer edge to edge upon asheet of paper as the latter is unwound from a roll. After the wood hasbeen treated as heretofore explained, the composite sheet may 5 be woundup in roll form. Consequently, this material may readily be manufacturedby a continuous process; the paper being progressively unwound from aroll; the veneer being applied to the paper as the latter is unwound;the com- 1o posite sheet being operated upon to slit the veneer andstress it transversely of the grain to the rupture point; and thecompleted product being then progressively rolled up. The process ofmanufacture 'of the composite material is, of l5 course, very rapid whenit is done continuously. However, in order that it may be continuous andnot intermittent, as will be the case when the gluing is done in hotpresses, I employ a glue that permits instantaneous gluing to beeffected. So- 20 dium silicate is such a cement or glue. The sodiumsilicate is spread on the paper just an instant before the wood isapplied, whereupon the passing of the paper with the overlying veneerthrough pressure rolls causes the veneer and the 25 paper to be firmlycemented together. Not more than a few seconds should elapse between thetime of spreading the sodium silicate on the paper and the time ofpressing the veneer against the same. 30

A box, the body of which is constructed of my improved material, isstrong and durable. The paper gives diagonal bracing tothe wood. Thewood protects the paper from contact with the contents of the box sothat, if the contents are 35 damp, as in the case of meat, the box isnot weakened as it is in the case of a berboard box containing dampgoods. It will also be seen that by constructing the end cleats asshown, the tension of the paper at the ends assists the shear strength40 to keep the end walls or heads from being pushed out.

I claim:

1. A board of wood cut partly through the same along parallel linesextending in the gen- 45 eral direction of the grain from one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in eect consists of 5o a series of parallelstrips connected together at their edges by strand-like cross pieces.

2. 'Ihe method of treating a board, which consists in cutting partlythrough the same along parallel lines extending in the general direction55 of the grain from one end of the board to the other, and then bendingthe board along each of said lines until the uncut portion there isruptured and forms connecting strands between the parts of the board onopposite'sides of that line. 60

3. A board of wood cut partly through the same along parallel linesextending in the general direction of the grain from one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured 65 along lines following the grain into strand-likeportions, whereby the board in effect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,the passages through the wood formed by the cuts and 70 the spacesbetween said cross pieces being lled with an elastic material bonded tothe wood.

4. A board of wood cut partly through the same along parallel linesextending in the general direction of the grain from one end of the 75board to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in effect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,the passages through the wood formed by the cuts and the spaces betweensaid cross pieces being filled with a material containing rubber latex.

5. A board of wood cut partly through the same along parallel linesextending in the general direction of the grain from one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in effect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,the passages through the wood formed by the cuts and the spaces betweensaid cross pieces being filled with rubber latex mixed with a finelydivided solid.

6. A board of wood cut partly through the same along parallel linesextending in the general direction of the grain from one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in effect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,and a layer of facing material covering a face of the board.

7. A board of wood cut partly through the same along parallel linesextending in the general direction of the grain from one end ofthe boardto the other, the uncut portions of the board inv the planes of the cutsbeing ruptured along lines following the grain into strand-likeportions, whereby the board in eiect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,the passages through the wood formed by the cuts and the spaces betweensaid cross pieces being filled with an elastic material bonded to thewood, and an elastic membrane covering and adhering to a face of theboard.

8. A board of wood cut partly through the same along parallel linesextending in the general direction cf the grain from one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in effect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,and a mixture of latex and finely divided solid material forming anelastic membrane covering a face of the board and filling`the passagesthat are caused to extend through the board by the 'cutting andrupturing thereof as aforesaid.

9. A board of wood cut partly through thesame along parallel linesextending in the general direction of the grain from one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in effect consists of a series of parallelstrips connected together at their edges by strand-like cross pieces,and a sheet of fibrous material covering a face of the board and securedthereto by an adhesive material.

10. A board of wood cut partlyl through the same along parallel linesextending in the general direction of the grain from. one end of theboard to the other, the uncut portions of the board in the planes of thecuts being ruptured along lines following the grain into strand-likeportions, whereby the board in eiect consists of a series of parallelstrips connected together at 5 their edges by strand-like cross pieces,a sheet of fibrous material underlying the board, and an elasticsubstance adhering to said sheet and filling the passages through thewood and the spaces between said cross pieces. m

11. The method of making a board exible and non-warping which consistsin cutting partly through the same along parallel lines extending in thedirection of the grain from one end to the other, and stressing theboard transversely to 15 the rupture point of the connecting piecesbetween the strips or sections defined by said lines to divide the boardinto strips held together by strand-like cross pieces.

12. The method of making a board flexible and non-warping which consistsin cutting partly through the same along parallel lines extending in thedirection oi' the grain from one end to the other, stressing the boardtransversely to the rupture point of the connecting pieces between thestrips or sections defined by said lines to divide the board into stripsheld together by strand-like cross pieces, and filling the spacesbetween the strips with an adhesive material that is flexible andelastic when it has set.

13. The method of making a board flexible and non-warping which consistsin cutting partly through the same along parallel lines extending in thedirection oi' the grain from one end to the other, stressing the boardtransversely to the rupture point of the connecting pieces between thestrips or sections defined by said lines to divide the board into stripsheld together by `strand-like cross pieces, and filling the spacesbetween the strips with rubber latex mixed with 40 finely divided solidmatter.

14. The method of making a board flexible and non-warping which consistsin cutting partly through the same along parallel lines extending in thegeneral direction of the grain from one end to the other, stressing theboard transversely to the rupture point of the connecting pieces betweenthe strips or sections defined by said lines to divide the board intostrips held together by strand-like pieces and produce open passagesextending entirely through the board between the strips, coating a sheetof waterproofed felt with glue, depositing on the glue layer an adhesivematerial containing latex, and pressing the said board down on the sheetof felt with sufficient force to cause the saidadhesive to iiow up intosaid passages.

15. The method of making a board flexible and non-warping which consistsin cutting partly through the same along parallel lines extending in thegeneral direction of the grain from one end to the other, stressing theboard transversely to the rupture point of the connecting pieces betweenthe strips or sections defined by said lines to divide the board intostrips held together by strand-like pieces and produce open passagesextending entirely throirgh the board between the strips, coating asheet of waterproofed felt with glue, depositing on the glue layer anadhesive material containing latex, and pressing the said board down onthe' sheet of felt with sufficient force to cause the said adhesive toow up into and completely ll said passages.

ARMIN ELMENDORF.

